CNN  — 

A unique US Open ended with, fittingly, a final out of the ordinary.

Dominic Thiem became the first player in the Open Era, which began in 1968, to rally from two sets down and win a US Open final when he beat his friend, Alexander Zverev, 2-6 4-6 6-4 6-3 7-6 (6) in New York on Sunday.

It hadn’t been done altogether since 1949.

And there were more firsts. The popular Austrian became the first new men’s grand slam champion since Marin Cilic in 2014 and it was the first fifth-set tiebreak in a final at the US Open.

Thiem somehow prevailed in the four-hour classic despite appearing to suffer from leg cramps in the tiebreak.

“We started to know each other back in 2014 and straight away started to develop a great friendship,” Thiem said during the trophy presentation. “We’ve made great things happen on the court and off the court. It’s amazing how far our journey brought us, to share this moment. I wish we could have two winners today. We both deserved it.”

Zverev, incredibly, lost from two sets up after coming from two sets down to beat Pablo Carreno Busta in the semifinals. Further, the German led by a break in the third but more devastatingly for him, couldn’t serve out the encounter at 5-3 in the fifth.

You could understand his tears during the trophy presentation. Both his parents tested positive for the coronavirus, he said, and couldn’t be with him in New York.

“I miss them,” he said, before stepping away from the microphone. “Man, this is tough. I’m sure they’re sitting at home and even though I lost, they’re pretty proud.”

Austrian Dominic Thiem lays on the court after winning the men's singe US Open tennis championships on Sunday, September 13.

A tournament marked by comebacks

Perhaps Thiem’s comeback wasn’t entirely a surprise, since huge comebacks marked the tournament’s previous two days. After Zverev turned the tables on Friday, in Saturday’s women’s finale Naomi Osaka overcame a set and nearly 3-0 hole to top Victoria Azarenka.

Roger Federer and Rafael Nadal both skipped the same major for the first time since 1999 and world No. 1 Novak Djokovic was defaulted in the fourth round for hitting a ball that inadvertently struck a line judge in the throat.

But even more unusual, yet understandable, than that this year was the US Open being held without fans due to the coronavirus pandemic but with a bubble in place.

Thiem might have benefited from the absences of the legendary Big Three, but the 27-year-old has downed each of them at least four times.

A grand slam title was coming, given his spot in three other finals at majors.

Thiem will no doubt be asked by reporters if an Achilles injury he suffered in the semifinals against 2019 finalist Daniil Medvedev contributed to his nervy, lethargic start on Arthur Ashe Stadium. He wouldn’t be the type to say if it was, however. He simply might have felt the pressure of being the significant favorite given his better ranking and 7-2 record against Zverev.

But the seventh-ranked Zverev – who struggled early in his previous two matches as the sizable favorite – cruised in the opening two sets in his first grand slam final.

When the ATP produced its NextGen slogan several years ago to promote its young stars, he was the head of the class.

A match with plenty of twists

Thiem secured victory on this third championship point.

The 23-year-old clocked serves in excess of 130 miles per hour, one forehand topped 100 miles per hour and he combined attacking tennis with counterpunching. He even successfully served and volleyed, taking advantage of Thiem’s deep return position. But 15 double faults eventually undid him.

The lone dicey moment for Zverev in the first two sets came midway in the second. A combination of bold tennis from Thiem and the double faults from Zverev – they have been an issue for him – saw a 5-1 lead dwindle to 5-4.

On his fifth set point, though, Zverev officially took a two-set advantage. It got even better for him when he broke for 2-1 in the third.

Now faced with the pressure of trying to close out a grand slam final, Zverev’s level dropped and Thiem’s rose.

Thiem immediately broke and then broke again at 5-4 to prompt a fourth set.

Thiem set up a break point at 2-3 after winning one of the rallies of the tournament, speedily defending around the court before hitting a forehand passing shot down the line. In the absence of the fans his entourage roared him on. He didn’t break there but did so at 4-3.

Thiem has the ability to steamroll opponents with his power game and when he broke for 1-0 in the fifth, it seemed like it was about to happen once again.

But suddenly in the position of favorite, as he was at the start, he buckled for 1-1.

Roller coaster fifth set

Then came another terrific rally, at 0-15. This time it was Zverev defending heroically before engineering a volley winner off a fierce Thiem backhand.

Zverev routinely pressured Thiem on serve thereafter and got his reward at 4-3. As the pressure continued to shift so did the score. Zverev was broken at 5-3 and Thiem produced magic to escape from 15-30 at 4-5, capping the game with a sizzling forehand pass.

Zverev sagged and erred on a forehand to trail 5-6.

But the twists weren’t over.

Thiem was ailing, calling for the trainer. He wasn’t moving freely, was broken himself and fell behind by an early mini-break in the tiebreak.

Two Zverev double faults gifted him a reprieve and Thiem built a 6-4 lead. The first two match points were erased. On the first, Thiem missed a forehand sitter with Zverev stranded.

But at 6-6, he ripped another passing shot to earn a third championship point. He then sealed it on a Zverev backhand error and sunk to the court.

Thiem joked that he might have to call Andy Murray if he lost Sunday, since the Scot fell in his first four grand slam finals before breaking through.

He might still want to call Murray. They can chat about what it feels like to hoist a major trophy.